1. Field of Invention
This invention generally relates to the field of Anesthesiology, specifically to airway management.
2. Prior Art
Flexible fiberoptic intubation of the trachea allows for placement of an endotracheal tube (ETT) with minimal manipulation of the patients airway. A significant disadvantage of this technique is that, for an image to be seen, an “airspace” (a space void of visual obstruction) must be created. If the tip of the fiberoptic scope is touching the patient's airway or any foreign objects in the patient's airway, the result would be analogous to leaving the lens cap on a camera and the necessary anatomy would not be seen. For this reason, inventors of medical devices have attempted to design instruments which both 1) displace airway anatomy to create the needed “airspace” and 2) act as a conduit through which a flexible fiberoptic scope with an ETT threaded over it can pass.
Multiple devices attempt to facilitate fiberoptic intubation via specially designed oral airways. U.S. Pat. No. 4,338,930 is an oral airway with an ellipsoidal cross-sectional shape which allows the passage of an ETT-sheathed fiberoptic scope and has a distal end which is open along its lingual surface to facilitate said passage. Two important disadvantages of this design are that 1) the static conformation of the distal end can not actively displace airway obstructions and 2) once the ETT is passed via the device, the proximal end of the tube must be disassembled to allow the device to be removed, carrying significant risk of inadvertent repositioning of the tube. The first above disadvantage was addressed by Greenberg (U.S. Pat. No. 5,443,063) who designed an intubating oral airway with a proximal end similar in function to that of Williams, but added a distal inflatable cuff to displace oropharyngeal obstructions. While addressing the first-listed disadvantage, the design of U.S. Pat. No. 5,443,063 does not address the second. U.S. Pat. No. 4,553,540 is a device with upper and lower hinged/articulated segment which act together to displace oropharyngeal obstructions but, like U.S. Pat. No. 5,443,063, does not permit the passage of an ETT via its lumen. U.S. Pat. No. 5,024,218 (via flexible guidewalls which allow removal of the device after intubation) addresses the second disadvantage but does not actively displace oropharyngeal obstructions. Another device which allows for removal of the device after intubation is WIPO Patent Application WO/2008/083368 which works via a two-component system which can couple and uncouple around an endotracheal tube using magnets. However, similar to U.S. Pat. No. 5,024,218, WIPO Patent Application WO/2008/083368 does not have a segment that actively displaces the tongue anteriorly to create a larger lumenal airspace.
Insofar as I am aware no intubating oral airway formerly developed allows for both significant displacement of oropharyngeal obstruction and for device removal without manipulation of the ETT.